Rotary drum furnace for incinerating rubbish



March 18, 1969 w. KOECHER ROTARY DRUM FURNACE FOR INCINERATING RUBBISH Filed Aug. 16. 1967 lnvemor: WAL 7'51? KOECl/[f United States Patent 3,433,186 ROTARY DRUM FURNACE FOR INCINERATING RUBBISH Walter Koecher, Munich, Germany, assignor to Fellner & Ziegler G.m.b.H., Frankfurt am Main, Germany, a

firm

Filed Aug. 16, 1967, Ser. No. 660,994 Claims priority, application Germany, Aug. 18, 1966,

K 60,050 US. Cl. 11014 3 Claims Int. Cl. F23g 5/06; F23b 1/32 ABSTRACT OF THE DISCLOSURE Background of the invention The invention relates to incinerators or furnaces for burning rubbish or the like. More particularly the invention relates to a rotary drum or barrel furnace with a fioatingly journalled rotary drum or barrel that is provided with grate openings in the wall under which a supply housing is disposed which has outlet openings for air of combustion and has an intake and discharge aperture for rubbish or refuse opposite the bearing means of the drum or barrel and an igniting burner proximate the aperture.

In rotary drum furnaces known heretofore, the wall of the rotary drum is a frusto-conical wall which is enlarged in the direction of the input and discharge aperture with a ring at its wide end that extends conically in the opposite direction. At the connecting end with the frustoconical housing wall this ring has an outer flange by means of which the rotary drum is mounted for rotation by rollers in a frame that encompasses it at a distance. This frame is pivotable within limits about an axis which extends parallel to the plane of the input and discharge aperture. Below the frusto-conical Wall the supply housing for the air of combustion is disposed in such a manner that the air flows through the grate openings of this wall into the interior of the rotary drum. As a consequence of the conical shape of the wall of the rotary drum with a large aperture, hot gases of combustion that are only poorly dispersed in this drum leave the drum without heating it substantially, especially since due to the limited rocking movement of the drum it cannot be pivoted far enough for the gases of combustion to sweep sufiiciently over the drum wall as they leave the drum. As a result, large amounts of heat from these gases are not utilized. The limitation of the pivotal movement of the rotary drum is due to the fact that when the drum is swung upwardly, it moves away from the supply housing whereby the inflow of air of combustion into the rotary drum is limited.

In accordance with the invention this problem is alleviated in that the wall of the rotary drum or barrel is shaped in a manner that during the progress of the combustion it can be tilted into a pivotal position where a desired amount of heating of the rotary drum is insured without influencing the supply of the air of combustion.

Accordingly, it is an object of the invention to construct the rotary drum with a wall in the form of a spherical cap.

This measure makes it possible to tilt the rotatable drum to such a pivotal position where the adaptation of ice the burning characteristics and of the quantities of rubbish supply will permit the heating of the rotatable drum to a more or less high temperature. Thus with a large amount of fill of the drum with heavy combustible rubbish the drum is brought to a pivotal position where the projection of the input and discharge opening with respect to a horizontal plane is relatively small, because with such a position of tilt the hot gases of combustion sweep over a large area of the drum wall as they flow out through the intake and discharge aperture. On the other hand, in a tilted position with a greater projection plane, faster outflow with a smaller surface area swept over by the gases of combustion is obtained and is used when well burning rubbish in smaller quantities is to be processed. Above all, the spherical shape of the drum results in a particularly favorable exploitation of the heat radiation of the inner drum wall not covered by the rubbish, because the radiation is directed to the center of the calotte or cap due to this drum shape. The invention provides also the further advantage that the distance of the supply housing from the drum wall remains the same for any position of tilt so that the air of combustion can be utilized to the fullest extent. Furthermore, the space requirement of the spherical cap shape of the rotary drum is very small, so that the burning space of the rotary drum furnace can be held to small dimensions and the driving and journalling elements can be readily disposed externally of the combustion space. Finally, the removal of the non-combustible parts of the rubbish by lowering the intake and discharge aperture is favored by the constant curving of the drum wall.

A further rubbish burning furnace known heretofore has a cone-shaped rotary drum, the narrow end of which has a perforated disk forming a discharge opening on which a solid disk is fastened by way of spacing bolts and which is concentrically disposed on the free end of a drive shaft. The perforated disk can be closed with a lid by means of a manually operable threaded spindle drive. The drive shaft is tiltably journalled externally of the furnace to permit righting the rotary drum from its oblique position of operation into the vertical discharging position. This tiltability of the rotary drum into vertical position, however, demands a relatively great width of the furnace. In addition, the narrow discharge aperture tends toward clogging by bulky non-combustible rubbish.

Finally, a further known rubbish burning furnace is known which has the same discharging device but a nontiltable conically shaped rotary drum. The furnace is of vertically split construction, and one of the furnace parts thus formed, together with the rotary drum, as well as its drive that is disposed externally of this furnace part, is removable from the other furnace part by means of a carriage carrying these parts. While this form of construction permits of decreasing the width of the furnace, there still exists the danger of clogging of the discharge opening by bulky components, and besides, the difliculty of having to move out of the displacement path of the rotary drum the air supply nozzle which is arranged at a small distance below the wall of the rotary drum.

As compared to these prior art structures, the rotary drum furnace in accordance with the invention affords the advantage that the rotary drum, by virtue of its spherical calotte shape, requires little space in the furnace for its pivotal movement for the discharging, so that this space is so proportioned that merely the gases of combustion are allowed to flow freely; clogging of the discharge aperture cannot occur because the rotary drum is emptied through the intake or filling aperture, and finally, the movement of the rotary drum due to its spherical shape is not encumbered by the air supply housing, but this housing independently of the tilting movement of the rotary 3 drum is always spaced at the same distance from the wall of the drum.

Brief description of the drawings Further objects and advantages of the invention will become apparent from the following description of an embodiment of the invention as schematically illustrated in the accompanying drawings, in which FIG. 1 is a longitudinal central section of the rotatable barrel furnace and FIG. 2 is a section through a part of the furnace wall showing the bearing arrangement for the shackle.

Description of the invention A substantially rectangular or cubicular furnace 1 of fire clay is provided with a rotary barrel or drum 2, the mantle or housing 3 of which is in the form of a spherical cap or dome for incinerating rubbish or the like. The housing 3 is provided with grate openings 4 in the form of slots or bores and has a relatively large intake and discharge aperture 5. Opposite this opening 5 the rotary container 2 has a hub 6 which has secured in it a drive shaft 7. The container 2 is journalled by means of this shaft 7 in the bridge or yoke 8 of the U-shapd brace or shackle 9 which is disposed around the outside of the furnace 1. Two inwardly projecting axle pins or studs 11 are secured to the free ends of the legs of the tilting frame 9, and each of them is journalled in one of two pivot supports or bearings 13 which are disposed in opposite walls 12 of the furnace 1 and the geometric axis of which extends through the center point of the spherical cap parallel to the plane of the input and discharge aperture 5. A motor 14 for driving the shaft 7 is mounted on the yoke 8 of the tilting frame or shackle 9. The tilting frame 9 can be raised or lowered with a hand wheel 16 fastened to a threaded spindle 15, one end of which is secured by means of a ball and joint plate a proximate the bottom of the furnace and the mid-portion of which extends through a threaded nut 9a mounted on the yoke '8 of the tilting frame 9, and in this manner the barrel can be turned about the axle provided by studs 11.

A supply housing 17 is disposed below the rotatable drum or barrel 2 to which combustion air is fed through an axially movable conduit 18, which is discharged through discharge openings 19. Furthermore an igniting burner 20 is arranged in front of the input and discharge aperture 5 in a manner that the igniting flame reaches into the rotatable barrel 2. Above the input and discharge opening 5 a supply tube 22 for the refuse or rubbish and a chimney 23 for discharging the gases of combustion extend through the top of the furnace. In lieu of the chimney 23 a cyclone or blower may be provided into which the exhaust gases are tangentially fed and are conducted away by the immersion pipe or dip tube of the cyclone or blower, while the dust and ash particles carried along .4 by the waste gases are separated out by the centrifugal effect and drop to the furnace bottom. If necessary, combustible waste gases (carbon oxide, methane) can be recombusted by means of an additional burner and/or auxiliary air and in this connection heated to at least 900-4000 C. for eliminating odors of the waste gases.

Having now described the invention with reference to the embodiment illustrated in the drawings, the invention is not intended to be limited thereto, but what is desired to be protected by Letters Patent of the United States is set forth in the appended claims.

I claim:

1. A furnace for burning rubbish, comprising a housing, a rotatable container for rubbish supported in said housing, said container being of generally spherical shape and having perforations and presenting an aperture at one end serving simultaneously as intake and discharge aperture, support means engaging said container at a location opposite said aperture and drive means in engagement with said support means operative to rotate said container by way of said support means, a tilting frame or the like pivotally supported on said housing and carrying said drive means, said support means and said container operative to move said aperture of said container downwardly to discharging position, an air supply housing having a plurality of nozzles disposed below said container and an igniting burner disposed opposite said aperture.

2. A furnace in accordance with claim 1, where said housing presents pivot supports and said tilting frame has pivot pins in engagement with said pivot supports disposed along an axis extending generally parallel to the plane of said aperture and through the center of said container.

3. A furnace in accordance with claim 1, where said support means comprises a shaft extending externally of said housing, a brace supporting said shaft and having two legs each presenting an inwardly extending stud, said legs extending around opposite portions of said housing, said studs being pivotally supported in said opposite housing portions in axial alignment with one another and defining an axis extending centrally through said housing and container parallel to a plane in which said aperture is disposed and said container being movable about said axis in response to pivotal movement of said brace about said studs.

References Cited UNITED STATES PATENTS 1,835,147 12/1981 Drew -14 FOREIGN PATENTS 1,043,037 9/1966 Germany.

JAMES W. WESTHAVER, Primary Examiner; 

